1.　　实现扫雷游戏。以下saolei_main是扫雷游戏的函数，该函数的运行需要调用函数minefield（已经给出），除此以外，saolei_main内部有两个嵌套函数(Minesweeper.The following saolei_main is a function of the mine clearance games, the function of the operation need to call a function minefield (has), in addition to this, saolei_main internal, there are two nested functions)